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 Mallory dist problem 
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Joined: Sun May 12, 2013 5:21 am
Posts: 332
Location: Michigan
Ok just installed a brand new Mallory Max-fire in my sbc, I also made & tested new MSD plugs wires. Won't rev and pops out the exhaust, once I finally got it warm to set the timing exactly it still won't rev. I have checked the firing order over n over and over! 12.4 volts at the dist and the dist grd is bolted up with the main new welding cable ground. It idles fine but as soon as you rev it starts dropping cylinders and popping, it will forcefully rev to bout 3k but it's not pretty, so I know the rev limiter isn't cutting in early(rev limit set at 6200). It has a mild timing curve just to get it going and the vac advance is unhooked atm(tried with).

I'm out of ideas, before I swap back to my HEI

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Fri Jun 10, 2016 3:56 pm
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Joined: Fri Feb 08, 2013 2:37 pm
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Did you check all your new plug wires with an Ohmmeter to be sure they all have continuity and similar resistance per length?


Fri Jun 10, 2016 6:21 pm
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Joined: Sun May 12, 2013 5:21 am
Posts: 332
Location: Michigan
Yup all test in spec, only one failed and I had another box I've stole a few wires out of here n there, so I made a completely new wire and it tested good.

edit: still I'll add that to my list I'm about to try and put the cheap summit wires from the old HEI on just to rule it out.

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Fri Jun 10, 2016 6:32 pm
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They are resistance radio suppression type, not solid wire, eh?

Check the alternator output for AC voltage. Turn on all accessories, lights, radio, heater fan, wipers (don't scratch a dry windshield), etc, to put a load on it, rev the engine to about 3000 and with the volt meter on AC Volts check at the alternator output terminal. Should not be over one-tenth Volt AC.


Fri Jun 10, 2016 6:37 pm
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Joined: Sun May 12, 2013 5:21 am
Posts: 332
Location: Michigan
I just tried this
-routed coil wires far away from hot, nada
-swapped the coil wire for a know good one, nada
-swapped to the Mallory coil(part num they actually recommend), nada
-swapped the hei plugs wires, nada

Nothing made a diff acts the same, only thing left I can think to try is a direct hot from the batt instead of the HEI harness keyed hot that reads 12.4v

I tested the alt not long ago was like 14.7 I think, even at 3500rpm but it was acting funny on my volts gauge before I underdrove it some. I could have it tested but I've see then test good a few times and still be bad.

Could it be the batt like you suggested for the tach flutter?

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Fri Jun 10, 2016 7:27 pm
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Joined: Sun May 12, 2013 5:21 am
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Location: Michigan
It hasn't run long enough to warm up and hate to load it up trying to warm it up because I can't rpm it to 2k like normal.

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Fri Jun 10, 2016 7:28 pm
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The test is for AC volts, not DC volts. A failed diode will allow AC out of the alternator and anything electronic will freak out for sure and can possibly be damaged.


Fri Jun 10, 2016 7:40 pm
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BOOT wrote:
It hasn't run long enough to warm up and hate to load it up trying to warm it up because I can't rpm it to 2k like normal.

The load is on the alternator, not the engine.


Fri Jun 10, 2016 7:41 pm
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Joined: Sun May 12, 2013 5:21 am
Posts: 332
Location: Michigan
Since the new dist is the only electronic on the car I suppose that's a good possibility, would an auto parts store be able to test for AC? I'd rather not try n keep it running long enough for it to idle so I can get out and test it, getting a helper is too much of a hassle and I'd have to promise my 1st born.

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Fri Jun 10, 2016 7:57 pm
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Joined: Sun May 12, 2013 5:21 am
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Location: Michigan
Oh n by load it up I mean foul it up restarting it 100 times until it'll idle on it's own since I can't rev to 2k tah keep it from dying.

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Fri Jun 10, 2016 8:04 pm
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